Intrinsic asthma is an important clinical problem accounting for a significant fraction of adult asthmatics. A disproportionate number of severe, steroid-dependent asthmatics fall into this group. Relatively little is know about the role of T lymphocytes and tissue cytokine production in producing the eosinophilia of intrinsic asthma. We will study the relationship between T lymphocyte infiltration, cytokine production and eosinophilia in intrinsic asthma and compare these findings to those in allergic asthma. A better understanding of intrinsic asthma pathogenesis will provide important insight into more effective treatment of this condition.